[Ir. dil, dear, beloved, precious, profitable]. Also Treth Moccu Creccai. A druid of Osraige [Ossory] in the invading army of Lugaid mac Con who puts a spell on Lugaid's brother, Eógan (3). When Dil realizes that the royal Eógan is certain to be killed, he asks that his daughter Moncha be allowed to sleep with Eógan so that some of Dil's descendants may become king of Munster. Eógan is killed, and nine months later Moncha gives birth to Fiachu Muillethan, a name appearing often in Eóganacht and Munster genealogies.